WO2011134594A1

WO2011134594A1 - Discharge cone

Info

Publication number: WO2011134594A1
Application number: PCT/EP2011/001747
Authority: WO
Inventors: Stefan Hamel; Johannes Kowoll
Original assignee: Uhde Gmbh
Priority date: 2010-04-29
Filing date: 2011-04-08
Publication date: 2011-11-03
Also published as: AU2011247444A1; EP2563692B1; ZA201208938B; DE102010018841A1; EP2563692A1; KR20130113924A; UA107828C2; US20130202369A1; CA2796528A1; CN102892689A; BR112012027426A2; RU2012146438A; TW201201897A

Abstract

The invention relates to a device for discharging a fine-grained solid from a container (1), wherein the container has a discharge cone (5) in the lower area, which opens into a discharge opening and discharge device, means for fluidizing or loosening the solid are provided, the discharge cone has at least one offset in the form of a gap (10), said offset having openings (12), a gas can be fed through each of the openings of the gap-shaped offsets, each of the gap-shaped offsets is covered toward the center axis of the discharge cone, the gap-shaped offsets are not directed toward the center axis of the discharge cone, and wherein the gaps of the gap-shaped offsets are closed by cover pates (11), which have round or slit-shaped openings, and the gaps extend in the downward direction.

Description

discharge cone

The thermal conversion of solid fuels, such as different coal, peat, hydrogenation residues, residues, waste, biomass and fly ash or a mixture of these substances is often carried out under elevated pressure and high temperature with the aim of a synthesis raw gas with high energy content and / or with a composition favorable for further chemical syntheses. Possible thermal conversion processes may be, for example, the pressure combustion or the pressure gasification by the fluidized bed or entrained flow process.

Here, there is a need to crush the stored under atmospheric pressure and ambient conditions fuels to fine particles and bring them to the pressure level of the thermal conversion to allow a promotion in the pressure reactor. This requires the promotion and intermediate storage of finely ground fuels. To bring the fuel to the pressure level of the reactor, it is usually used lock systems in which the fuel is placed in successively connected containers on pressure. The decisive criterion for operational reliability is the reliable emptying of the containers, even after they have been brought to high system pressures.

In order to discharge microparticulate and fine-grained solids safely from a container, various approaches are possible according to the relevant prior art in principle:

In large silos under atmospheric pressure, the solid often becomes contaminated with mechanical devices, e.g. Clearing arms, etc., deducted.

• In principle, the solids bed can be converted into the fluidized bed state by gas supply against gravity. The fluidized bed behaves then similar to a liquid and can leak through outlet openings, side nozzles, etc. The disadvantage is that large amounts of gas are needed. To complicate matters, it is very difficult to convert very fine particles into a homogeneous fluidized bed.

• A further possibility to enable the discharge of solids from a container is to take into account the bulk material properties. to provide for outlet geometries. The solids discharge from a cone can be assisted by adding gas over or to the cone walls. The amount of gas is typically less than the amount that would be required for fluidization, but sufficient to remove the wall friction of the bulk material and / or to prevent localized bridging approaches.

The latter method is the preferred variant in the described gasification plants, in which fine-grained fuel must be handled both at atmospheric and at high pressures. Here, the required amount of gas is limited and dispensed with mechanical installations at the same time.

[0006] The state of the art is to supply gas via porous elements into the discharge cosine. The porous elements are preferably made of sintered metal, but may also consist of other porous media. The use of porous materials has some procedural and operational disadvantages:

• The permissible pore size is based on the solid to be handled or on its particle size distribution. The pore size can only be reduced to a reasonable level, which results from the desired retained particle size and the Durchströmungsdruckverlust. In practice, it can be stated that even with very small pore sizes, the porous medium becomes clogged over time. The reason for this is that the finely ground fuel to be handled always has a particle size distribution, in which even the finest particles are present, which can be put into the pores. In addition, abrasion effects of the fuel within the container and during handling lead to the formation of extremely fine particles which would also clog the pores. While attempts are made to counteract the clogging of the porous media by permanently giving off a gas flow, the practice shows that this can only extend the life of the porous elements, but the fundamental problem remains.

• Porous material inevitably has a lower strength than comparable solid material and may therefore only be operated with gas so that a maximum allowable pressure drop over the porous material, ie a mechanically acting force resulting from the pressure difference and the overstretched area, is not exceeded. Improper handling or unsecured pressure increases during operation can therefore lead to destruction of the porous material.

• Another procedural disadvantage is that porous materials may only be charged with particle-free gas. It is not possible e.g. to use gas generated from vessel depressions and particle-contaminated gas, since the porous materials would clog up from the gas feed side.

• The processing of the porous material in conjunction with the steels used in classic container construction requires special manufacturing skills and experience, especially in the case of a high-quality welding of, for example, sintered metals. This is especially expensive.

In DE 41 08 048 C2 gas supply elements are introduced in the conical part of a pressure pot to achieve a fluidization of the solid bed, with the aim to accomplish a pneumatic delivery from the pressure pot out. These pipe elements are mounted on the inner sides of the cone, which are equipped with holes for gas supply.

In EP 348 008 B1 it is proposed to ensure a constant mass flow of solids from a container with a conical outlet by gas is fed through a vertically from above, centrally introduced tube into the bed of solids in the vicinity of the outlet and in the conical container part. In addition, gas is supplied via the cone walls, wherein the cone walls are designed as a porous medium.

In WO 2004/085578 A1 a lock container is presented, which provides inside the conical container part gas supply elements over which the container is brought to target pressure. The elements are provided with porous elements through which the gas is supplied.

In US 5, 06.240 A, a cone is proposed, which provides a plurality of porous elements, is placed on the gas in the bed of solids, with the aim to set a uniform flow of solids.

In WO 89/11378 A1, it is proposed to supply gas by introducing porous elements into the cone of a silo, in order thereby to ensure uniformity. allow material flow. The same is attempted with the gas supply device of US 4,941, 779 A. The difference is that the described device is immersed in the bed, where it partially supplies gas to also ensure the most uniform flow of material from an intended sequence. Again, porous elements are used to guide gas into the bed of fine particles.

US 2006/013660 A1 describes in detail a fluidizing cone including the required connecting flanges, which is attached to a container. The conical inner walls are according to the description of porous material.

CH 209 788 describes a reservoir for dusty goods with opening into a downcomer funnel, in which a thin layer of air migrates to the funnel wall against the down pipe, without approaching the funnel center, while rising through the center of the funnel upwards Air pushes the dust out to the funnel wall and prevents the formation of bridges.

There is therefore the object of providing a gas discharge discharge cone for discharging a fine-grained solid from a container, which overcomes the procedural disadvantages when using porous materials and thereby fulfills the following requirements:

• no use of porous materials,

Independence from the particle size distribution of the bulk material,

The applicability of particle-laden gases for the application of gas,

• No limitation of the permissible pressure loss.

The discharge cone according to the invention solves this problem,

Wherein the container has a discharge cone in the lower region,

Which opens into a discharge opening and discharge device,

Means are provided for fluidizing or loosening the solid,

The discharge cone has at least one offset in the form of a gap, A gas can be fed through each of the openings of the gap-shaped offsets,

• characterized in that

Each of the gap-shaped offsets is concealed towards the center axis of the discharge cone,

• The gap-shaped offsets are not aligned with the center axis of the discharge cone, and wherein

The gaps of the gap-shaped offsets are closed by cover plates which have round or slot-shaped openings,

• the gaps run in a downward direction.

In one embodiment, it is provided that the gaps are formed by laterally overlapping cone sectors. In further embodiments, it is provided that the gaps run in an oblique direction and the gas outlet side is aligned in a spiral manner in both the tangential and in the direction of the outlet opening, and therefore also has a radial-vertical component. It can further be provided that the gaps are formed by overlapping portions in the form of oblique conic sections.

Further embodiments relate to the gaps and their openings through which gas is added. Thus, the gaps may be closed by cover plates having round or slot-shaped openings. The openings may also be formed in a nozzle shape. Advantageously, the openings are larger than the largest particle diameter of the solid in the discharge cone. The thickness of the cover sheets may be selected to be 3 times larger than the bore diameter to impart a direction to the gas jet. The openings can be provided at smaller intervals in the upper area of the column than in the lower area of the column. The holes in the upper region may also have larger cross sections than in the lower region, so that a gas flow which is related to the cone cross-sectional area and adapted to the respective height can be supplied.

Instead of holes, outlet pipes or the outlet nozzles can be used in further advantageous embodiments, wherein the spatial angle at which the gas jet enters the discharge cone, are selectable. Ideal are - depending on the material to be picked - angle to the horizontal from 30 degrees upwards or directed downwards, and directed up to 45 degrees in the horizontal plane, measured from the circular tangent abutting the gas exit point, inwardly toward the center axis of the discharge cone.

The device of the invention will be explained with reference to 5 drawings, these drawings are only exemplary embodiments of the construction of the device according to the invention.

1 shows a storage container 1 with a discharge cone 5 according to the invention,

2 and 3 show a Austragskonus with columns that extend in the vertical direction,

Fig. 4 shows a variant with modified inlet openings

Fig. 5 shows a Austragskonus with columns having an oblique angle to the central axis.

Fig. 1 shows a storage container 1 with a discharge cone 5 according to the invention, in which the finely ground fuel 2 is conveyed pneumatically or gravimetrically. The gas 3 leaves the storage container 1 via the gas filter 4, while the finely ground fuel reaches the storage container 1, where it sinks into the discharge cone 5. The gas 3 is in the case of a pneumatic filling of the storage container 1 from the conveying gas and from the gas, which is displaced by the introduced solid in the container. In the case of a gravimetric filling, the gas 3 consists essentially of displaced gas. The discharge cone 5 encloses a pressure jacket 6, which is acted upon by compressed gas 7. The deduction 9 of the finely ground fuel takes place through the lock 8.

2 and 3 each show a Austragskonus 5 with columns 10 which extend in the vertical direction, and from which the gas 3 flows in the tangential direction. Fig. 2 also shows half the opening angle γ of the discharge cone. The gaps are closed with sheets 11, in which bores 12 are introduced, can be introduced through the compressed gas 7 from the pressure jacket 6 in the discharge cone 5. While FIG. 3 shows columns 10 which are concealed, as viewed from the center line, and have a step 13, the columns 10 shown in FIG. 2 are open. The variant shown in FIG. 3 has the advantage that no bulk cone can build up in front of the bores 12 and a backflow of finely ground fuel 2 through the holes 12 into the pressure jacket 6 is then omitted, when no gas pressure is being applied there, such as intermittent operation. However, the variant in Fig. 3 is somewhat more expensive to build.

Fig. 4 shows the variant shown in Fig. 3 with modified inlet openings to reduce the high stress of the cone wall by the tangential outflow of the gas jet from the opening in the gap 10. The inlet openings are here modified so that the beam direction of the exiting gas jet can be spatially aligned. This can be achieved structurally by making the sheets 11 (not shown in FIG. 4) in the columns 10 very solid and correspondingly fine holes 12 provides that are embedded in defined angles in the sheets 11, or by thin sheets 11 provides, on which thin outlet pipes or outlet nozzles 14 are mounted, the example can be aligned by simply bending in the right direction. Preferably, such outlet tubes or outlet nozzles 14 are mounted flush on the inner side of the cone and thereby projecting on the side facing the outer space, so that it is possible to align the jet direction with simple means on the projecting side.

For the alignment of the outlet tubes or the outlet nozzles 14, the following angles are advantageously established. This is based on a Cartesian coordinate system having its point of origin in the puncture point, whose one vertical y-z plane is parallel to the cone central axis and whose other vertical x-y plane intersects the cone central axis, and whose third x-z plane is the horizontal plane. 4, the angles of the axis of the outlet tubes and the outlet nozzles 14 on the outside of the discharge cone, where they can be easily measured in the mounted state. The same applies analogously to the corresponding gas outlet angles into the discharge cone.

Here, the angle α between the projection 15 of the beam axis, which corresponds to the axis of the outlet tubes or the outlet nozzles 14, on the horizontal xz plane, and the tangent 16, which rests on a horizontal section of the cone and through the origin point of the coordinate system runs, between 0 and 45 degrees. Further, the angle β between the beam axis corresponding to the axis of the exhaust pipes or the exhaust nozzles 14 and the horizontal xz plane is in the range of 30 degrees upward to 30 degrees downward. Fig. 5 shows a further discharge cone with downward columns 10, which extend in a spiral direction. The columns 10 are also closed with sheets 11, in which holes 12 are recessed, can be introduced through the compressed gas 7 from the pressure jacket 6 in the discharge cone 5. Due to the spiral arrangement, a discharge behavior of the finely ground fuel can be achieved as in a liquid nozzle.

[0026] List of Reference Numerals

1 storage container

2 Finely ground fuel

3 gas

4 gas filters

5 discharge cone

5a center line of the discharge cone

6 pressure jacket

7 compressed gas

8 lock

9 deduction

10 columns

11 sheets

12 holes

13 paragraph

14 outlet pipes or outlet nozzles

14a Center line of the outlet tubes or outlet nozzles

15 projection

16 tangent

Claims

claims

1. Device for discharging a fine-grained solid from a container,

Wherein the container has a discharge cone in the lower region,

Which opens into a discharge opening and discharge device,

Means are provided for fluidizing or loosening the solid,

The discharge cone has at least one offset in the form of a gap,

• a gas can be supplied through each of the openings of the gap-shaped offsets, characterized in that

• the gaps run in a downward direction.

2. Apparatus according to claim 1, characterized in that the gaps are formed by laterally overlapping cone sectors.

3. Apparatus according to claim 1, characterized in that the gaps extend in an oblique direction and the gas outlet side is aligned spirally in both tangential and in the direction of the outlet opening.

4. Apparatus according to claim 3, characterized in that the gaps are formed by superimposed overlapping portions in the form of oblique conic sections.

5. Device according to one of claims 1 to 4, characterized in that the openings are formed in a nozzle shape.

6. Device according to one of claims 1 to 5, characterized in that the diameters of the openings are larger than the largest particle diameter of the solid.

7. Device according to one of claims 1 to 6, characterized in that the thickness of the cover plates is selected at least 3 times larger than the bore diameter.

8. Device according to one of claims 1 to 7, characterized in that the openings are provided in the upper region of the column at smaller intervals or have larger cross-sections than in the lower region.

9. Device according to one of claims 1 to 8, characterized in that the center lines of the openings form an angle between 0 degrees and 45 degrees with respect to a tangent applied to the Austragskonus in the horizontal projection.

10. Device according to one of claims 1 to 9, characterized in that the center lines of the openings are inclined relative to the horizontal at an angle between 0 and 30 degrees upwards or downwards.